Mill for manufacture of plaster concrete articles

ABSTRACT

A mill is disclosed which is provided with a device for feeding plaster concrete wastes back to a concrete mixer, said device comprising means for receiving and crushing the wastes, as well as means for conveying said wastes back to the concrete mixer.

111111611 States Patent 1191 Birger et al.

[ MILL FOR MANUFACTURE OF PLASTER CONCRETE ARTICLES [76] Inventors AbramIsaakovich Birger, Prospekt Mira, 184, korpus 2, kv. 167; AlexandrMikhailovich Fiskin, Prospekt Mira, 184, korpus 2, kv. 21 1; IvanSergeevich Samsonov, Zuezdny bulvar, 5, kv. 23; Anatoly AlexandrovichSavushkin, 2 Novo-Ostankinskaya ulitsa, 14, kv. 5; Nikolai NikolaevichZemtsov, Prospekt Mira, 184, korpus 2, kv. 164; Vitaly ArkadievichBorisevich, Zvezdny bulvar, 5, kv. 174, all of Moscow, U.S.S.R. I

Filed: May 4, 1972 [21 Appl. No. 250,169 g 52 US. Cl..425/217,425/218,425/220, 1 5 425/432 51 1111. c1 ..B28b 3/12,B28b 5/02Primary Examiner-J. Spencer Overholser Assistant Examiner-David S.Safran Attorney, Agent, or Firm-Holman & Stern ABSTRACT A mill isdisclosed which is provided with a device for feeding plaster concretewastes back to a concrete mixer, said device comprising means forreceiving and crushing the wastes, as well as means for conveying saidwastes back to the concrete mixer.

1 Claim, 5 Drawing Figures PATENTEDHAYZI I974 SHEET 2 [IF 5 PATENTEDMYPI197 SHEEI S 0? 5 lli/4 F/GJ . 1 MILL FOR MANUFACTURE OF PLASTER CONCRETEARTICLES BACKGROUND O THE INVENTION This invention relates generally toequipment used for manufacturing plaster Concrete articles by way ofcontinuousrolling thereof and more particularly, it relates to mills forthe manufacture of plaster concrete articles. Y

The method of manufacturing plaster concrete articles by way ofcontinuous rolling thereof is the most advanced one in that with littlelabour consumption, it is possible to obtain articles of uniformphysical and mechanical properties with accurate dimensions, having highquality in the surfaces.

Articles made of plaster concrete are used for making various partitionwalls in dwelling houses, public buildings, and lavatory and bathcabins. Such articles may also be used as lining materials for the innersurfaces of main walls, as well as for floor slabs being laid underparquet or plastics.

Prior art mills for manufacture of plaster concrete articles by way ofcontinuous rolling thereof comprise a conveyor with upper and lowermoulding strands and mount a concrete .mixer, a gauging drum with a' setof gauging rolls and a vibrating unit. I I

In conventional mills articles, e.g. plaster concrete articles,are'manufactured by means of a continuous supply of a plaster concretemixture prepared in a concrete mixer 'ontoj'the surface of the moulding(lower) strand of the mill, theframeworks of panels to be manufacturedbeingplaced on the strand beforehand, as it advances, to serve asmoulds.

The vibrating unit operates in an intermittent manner to ensure betterdistribution and compaction of plaster concrete mixture.

.The frameworks being filled uniformly with plaster concrete mixturealong the whole width thereof, are moved under the gauging drum to theset of the gauging rolls which define the final thickness of mouldedarticles and cover them with the upper moulding strand.

Experiences in operating the above-described mills have shown thatduring the manufacture of plaster con crete articles, material wasteswill inevitably appear, said material wastes being formed mainly fromfilling with the door ways, window openings, etc., of the panels beingmanufactured.

In accordance with the available statistical data, the

amount of such material wastes constitutes, on the average, 6-8 percentof the total volume of the plaster concrete required to manufacture thearticles.

Until recently plaster concrete wastes formed in the course of operationof millsof the above-described type have not been utilized. However,research and experiments have shown that plaster concrete wastes can beused as an active filler 'in the manufacture of plaster concretearticles.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a mill for the manufacture of plaster concrete articles, thatwill make it possible to save inactive raw materials by utilization ofplaster concrete mixture wastes.

The objectives of this invention areaccomplished by a mill for themanufacture of plaster concrete articles by way of continuous rollingbetween the upper and lower endless moulding strands of plaster concretemixture which is fed into a mould from a concrete mixer. According tothe present invention, a device is provided which is adapted for feedingplaster concrete wastes back to the concrete mixer, said devicecomprising a unit which is located at the point of separation of amoulded article from the lower moulding strand which receives saidwastes, means for receiving and a crushing wastes, and means associatedwith said unit to convey said wastes back to the concrete mixer.

The subject-matter of the present invention consists in the following:

Due to the provision of the mill with the device for feeding'plasterconcrete wastes back to the concrete mixer, plaster concrete wastes areremoved from the moulded article as excess material which remains on thefilled-up framework at the moment of separation of the moulded articlefrom the lower moulding strand during the movement thereof. The wastesthus removed are fed to the receiving means and, then, to the crushingmeans.

After being crushed, the wastes are conveyed to the concrete mixer to bemixed with plaster concrete mixture, thereby partially substituting theinactive filler thereof.

The present invention provides for almost complete utilization of wastesduring the manufacture of plaster concrete articles and, consequently,the consumption of the .inactive fillers used for the preparation of theplaster concrete mixture is lowered by 5-6 percent.

BRIEF DESCRIPTION OF THE DRAWINGS The following description of anexemplary embodiment of the mill for the manufacture of plaster concretepanels is given with reference to the accompanying drawings, in which:

FIG. 1 is a side elevation'al view of the mill according to the presentinvention;

FIG. 1 is a side elevation view of the mill according to the presentinvention;

FIG. 2 is a top view of the mill;

FIG. 2' is top plan view of the mill according to the present invention;and

, FIG. 3 is a sectional taken along line Ill-III in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to theaccompanying drawings, a mill for the manufacture of plaster concretepanels comprises a conveyor which is essentially two endless moulding,upper l and lower 2, strands (FIGS. 1 and 2); a gauging drum 3 with aset of gauging rolls 4 disposed above the upper moulding strand 1; avibrating device 5 disposed under the lower moulding strand 2, asingle-shaft continuous-operation concrete mixer 6 located above theconveyor; a charging-and-batching device comprising four hoppers 7provided with volumetric batching units 8 located thereabove; a devicefor feeding plaster concrete wastes back to the concrete mixer 6 whichis essentially a means for receiving wastes from the strand made as ahopper 9 and located at the point of separation of a moulded articlesfrom the lower moulding strand 2, a means for crushing wastes made as anauger being connected to said receiving means. The blades 11 are mountedon the end surface of the body of the auger 10.

Said conveying means are essentially a horizontal conveyor 12 disposedunder the auger body and an inclined conveyor 13. At one side, saidconveyor 13 adjoins said horizontal conveyor 12 and at the other side,it adjoins an auger 14 disposed above the concrete mixer 6. One end ofthe conveyor formed by the two endless moulding strands l and 2 isconnected to a power driven receiving roll table 15, the other endthereof being adjacent to an over-running roll table 16 which isterminated in a tilter 17.

The unit for receiving and crushing wastes may comprise other deviceswhich accomplish the sametasks and may be fashioned, for instance, as ahorizontal jaw crusher having a body which is adapted to receive wastesto be crushed. Alternatively, a system of augers may be used as themeans for conveying crushed wastes to the concrete mixer, said augersbeing arranged in such a manner as to ensure continuous delivery ofwastes to the concrete mixer.

The mill for the manufacture of plaster concrete panels shown in theaccompanying drawings functions as follows.

Wooden frameworks of external wall panels with window openings arecontinuously placed one after another on the receiving roll table (FIGS.1 and 2), and are conveyed in the direction indicated by arrow A" ontothe lower moulding strand 2 in the zone of delivery of plaster concretemixture.

Dry components (plaster, saw-dust and sand) of the mixture are suppliedfrom the hoppers 7 through the volumetric batching units 8 to thesingle-shaft continuous-operation concrete mixer 6, which is alsosupplied with water necessary for preparing the plaster concretemixture.

The plaster concrete mixture thus prepared is poured as a continuousflow onto the lower moulding strand 2 through a discharge opening (notshown) and fills the wooden frameworks disposed on said strand.

Due to the reciprocating movement of the concrete mixer 6 located abovethe moulding strand 2 and the periodical actuation of the vibrating unit5, the plaster concrete mixture is uniformly distributed along the widthof the strand 2.

The wooden frameworks being filled with the plaster concrete mixture areconveyed to under the upper moulding strand 1 and are covered thereby.

Then, the gauging drum 3 and the set of gauging rolls 4 performcompaction and gauging of panels until the required thickness isobtained.

While being between the upper and lower strands 1 and 2, the mouldedplaster concrete panels get set and become ready for striking at thepoint of separation from the lower moulding strand 2.

The excess material, being formed in window openings and in front of theleading panel during the starting of the mill, i.e., plaster concretewastes, are removed at the point of separation of panels from the lowerstrand 2 and are fed into the hopper 9 of the device for feeding backthe wastes. The panels are further conveyed to the over-running rolltable 16 which is driven by two drives, by the drive of the lowermoulding strand 2 and by its own drive that imparts to it a speed whichis ten times higher than the speed of the lower moulding strand 2. Thisincrease in the speed provides for a time reserve that is necessary forsubsequent technological operations (tilting, finishing of the panelface, etc.).

The panel is transferred to the tilting device 17 at an increased-speed,said panel being brought from the horizontal position to the verticalone, and transported further for drying.

The plaster concrete mixture wastes, being obtained in the hopper 9, areconveyed by the auger 10 (FIG. 3) to its face surface in the directionof the blades 11 which perform the crushing of the wastes.

The crushed wastes are supplied onto the horizontal conveyor 12 througha discharge port 18 (FIG. I) and, then they are transported by theinclined conveyor 13 to the auger 14 which feeds them into the concretemixer 6.

In the concrete mixer, the crushed wastes are mixed with newly supplieddry' components to serve as an inactive filler of the plaster concretemixture.

As it has been shown above, the mill, according to the invention,ensures a rather complete utilization of plaster concrete wastes duringthe manufacture of moulded panels, thereby providing for savings in theinactive raw materials.

We claim:

1. In a mill for manufacturing plaster concrete articles, comprisingupper and lower moulding strands, plaster concrete articles being formedtherebetween in moulds through continuous rolling, a single-shaftconcrete mixer means for supplying the plaster concrete mixture into amould, means for returning plaster concrete wastes located at the pointof separation of a moulded article from said lower moulding strand, andsaid returning means including means for subsequently conveying saidwastes back to said concrete mixer means, the improvement comprises saidreturning means further including means for crushing said wastes, saidcrushing means being in the form of an auger with blades disposedthereon for crushing said wastes, said auger moving said wastes to saidmeans for conveying it back to the concrete mixer means.

1. In a mill for manufacturing plaster concrete articles, comprisingupper and lower moulding strands, plaster concrete articles being formedtherebetween in moulds through continuous rolling, a single-shaftconcrete mixer means for supplying the plaster concrete mixture into amould, means for returning plaster concrete wastes located at the pointof separation of a moulded article from said lower moulding strand, andsaid returning means including means for subsequently conveying saidwastes back to said concrete mixer means, the improvement comprises saidreturning means further including means for crushing said wastes, saidcrushing means being in the form of an auger with blades disposedthereon for crushing said wastes, said auger moving said wastes to saidmeans for conveying it back to the concrete mixer means.